Select individual hairs with Python
wip Answer

Via the Particle Edit Mode it is possible to subdivide single Hairs, therefore it should be possible to recreate this via python. One Constraint here is that the hair system is locked after editing it.

You have to tweak it a bit, but the basics are here, namely doing it via the depsgraph: devtalk.blender.org/t/manipulating-particles-in-python/7552/3